1. Field of the Invention
The present invention relates to an image forming apparatus operated according to an operation instruction signal from an operation unit.
2. Description of the Related Art
Conventional copiers, serving as one type of image forming apparatus, have been used widely and generally include an image reading unit on which an original is mounted, an image forming unit disposed below the image reading unit, and an operation unit fixed on the image reading unit.
A description will now be provided of the arrangement of the respective units, i.e, the image reading unit, the image forming unit and the operation unit, constituting the image forming apparatus having the above-described configuration with reference to FIG. 7. FIG. 7 is composed of a top plan view, a side view as seen from the operator, and a side view as seen from the sheet feeding side of the image forming apparatus. Since the internal configuration of each of the units is the same as that of a well-known image forming apparatus, further description thereof will be omitted.
When an original-pressing plate 60 provided on the top surface of the image forming apparatus is opened, an original is mounted on a platen-glass, and the apparatus is driven, an image reading unit 10 operates, and image information representing an image on the original is output. An image is formed on a recording material by an image forming unit 20 provided at a lower portion of the apparatus, based on the image information.
As is well known, in the image forming unit 20, an image is formed on a separately supplied recording material according to the operations of an image bearing member (not shown), and charging means, developing means, transfer means and the like disposed around the image bearing member. The recording material having the image formed thereon is discharged onto a discharged-sheet tray 50. Reference numeral 30 represents a sheet feeding cassette unit for accommodating sheets of the recording material, and reference numeral 40 represents a manual sheet feeding unit.
The operator instructs operations, such as on/off of the apparatus, selection of a copying mode, and the like, through an operation unit 70 mounted on the image reading unit 10. The operation unit 70 includes an operation display panel for displaying the above-described various operations, jam removing processing, and the like.
A description will now be provided of the actual state of use of the image forming apparatus with reference to FIGS. 8A-8C. FIG. 8A illustrates a configuration in which the apparatus is used as a copier by stacking the image reading unit 10 and the image forming unit 20 (a standard configuration). FIG. 8B illustrates a configuration in which the apparatus is used as a printer by removing the image reading unit 10 and connecting the image forming unit 20 to the output side of a computer. FIG. 8C illustrates a configuration in which the apparatus is used as an image reading apparatus for outputting image information from the image reading unit 10 to an external apparatus, such as a computer, a printer or the like.
By detachably mounting an automatic original-feeder 80 and/or a sorter 90 for classifying copies discharged to the outside of the apparatus on the image forming apparatus, the image forming apparatus can be used, for example, in a configuration in which the automatic original-feeder 80 is added to the standard configuration, in a configuration in which the sorter 90 is added to the standard configuration, and in a configuration in which the automatic original-feeder 80 and the sorter 90 are added to the standard configuration as shown in FIGS. 9A-9D.
In the above-described image forming apparatus, higher operational functions are being demanded in accordance with recent development in the image processing technique, and provision of network environment. In one of these functions, it is intended to improve operability in image processing by providing the same level of visibility and operability as in a manual operation by performing preview display.
However, if preview display is performed on a conventional display unit having a size of about 5 inches, since image processing is performed for a reduced pseudo-original, problems may arise in visibility and operability for detailed portions. A larger display unit is also preferable from the viewpoint of being adapted to an increase in the number of operational picture frames, operation buttons or the like required as a result of provision of higher functions to be added in accordance with development of a network configuration.
When the size of the display unit is increased, the size of a front portion of the apparatus where the operator is present is also increased, resulting in an increase in the distance between the operator and a portion where an original is to be mounted, and a degradation in operability. If the operation unit is inclined so as to extend to a lower front portion of the apparatus, the operation unit is over-lapped with the image forming unit, resulting in degradation in the jam removing capabillity and maintenance capability of the image forming unit.
Furthermore, conventionally, when it is intended to use an image forming unit of a copier configuration for a printer configuration or for a reader configuration, it is necessary to provide an operation unit for the printer configuration or the reader configuration separately from an operation unit for the copier configuration, resulting in an increase in the production cost.
Japanese Patent Laid-Open Application (Kokai) No. 6-320836 (1994) discloses a printer in which an operation panel is detachably mounted, and a position where the operation panel is mounted can be changed in accordance with the direction of installation of the printer.
Japanese Patent Laid-Open Application (Kokai) No. 10-243138 (1998) discloses a configuration in which an operation display device is detachably mounted on an image reading apparatus so that the operation display device can be purchased as an optional device.
However, even if the configuration disclosed in Japanese Patent Laid-Open Application (Kokai) No. 6-320836 (1994) or 10-243138 (1998) is adopted, an operation unit for a printer configuration and an operation unit for a copier configuration (operation units for instructing respective operations for an image reading unit and an image forming unit) are separately provided, thereby causing an additional cost.